Takeaway
- Existing evidence suggests an increased risk of venous thromboembolism (VTE) in tamoxifen users vs non-users and aromatase inhibitor (AI) users among women with a history of early breast cancer.
- Tamoxifen may have a protective association with vascular cardiovascular diseases (CVDs).
Why this matters
- Previous meta-analyses have reported the effect of adjuvant endocrine therapies on the risk of composite CVD outcomes.
- This review reports the effect on clinically specific CVDs.
- It establishes the need for clinical vigilance and possible preventive measures when prescribing endocrine therapies to women at risk of VTE.
Key findings
- Consistent evidence of increased VTE risk in tamoxifen users vs non-users.
- Decreased VTE risk with AIs compared directly with tamoxifen.
- Direct effect of AIs on VTE was less clear.
- Higher risk of myocardial infarction (MI) and angina with AIs vs tamoxifen.
- Inconsistent results for associations with AIs and stroke.
- Risk of peripheral vascular disease with AIs vs tamoxifen was inconclusive.
- Increased risk of heart failure with AIs vs tamoxifen in a single RCT was not replicated in an observational cohort study.
- Tamoxifen was associated with a decreased risk of heart failure compared to non-users, but with wide confidence intervals.
- Findings on risk of arrhythmia in tamoxifen users vs non-users were inconclusive.
Study design
- Systematic review and meta-analysis of 15 randomised controlled trials (RCTs) and 11 observational studies published on Medline and Embase up to June 2018.
- Funding: Wellcome Trust and Royal Society.
Limitations
- High risk of bias.
- Potential for missed studies.
References
References